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authorMario Preksavec <mario@slackware.hr>2017-10-20 20:56:55 +0200
committerWilly Sudiarto Raharjo <willysr@slackbuilds.org>2017-10-21 07:08:14 +0700
commit139c45ee8aed136d55ae25517e67cd103978c9c3 (patch)
tree0c1f8b0bb7353039941d468a024722add35b2d17
parentd7ebd09fcd7f59ba2cb12f45eecff627aec49860 (diff)
downloadslackbuilds-139c45ee8aed136d55ae25517e67cd103978c9c3.tar.gz
system/xen: XSA 237-245 update.
Signed-off-by: Mario Preksavec <mario@slackware.hr>
-rw-r--r--system/xen/xen.SlackBuild2
-rw-r--r--system/xen/xsa/xsa237-4.9-0001-x86-dont-allow-MSI-pIRQ-mapping-on-unowned-device.patch27
-rw-r--r--system/xen/xsa/xsa237-4.9-0002-x86-enforce-proper-privilege-when-mapping-pIRQ-s.patch66
-rw-r--r--system/xen/xsa/xsa237-4.9-0003-x86-MSI-disallow-redundant-enabling.patch55
-rw-r--r--system/xen/xsa/xsa237-4.9-0004-x86-IRQ-conditionally-preserve-irq-pirq-mapping-on-error.patch124
-rw-r--r--system/xen/xsa/xsa237-4.9-0005-x86-FLASK-fix-unmap-domain-IRQ-XSM-hook.patch37
-rw-r--r--system/xen/xsa/xsa238.patch45
-rw-r--r--system/xen/xsa/xsa239.patch46
-rw-r--r--system/xen/xsa/xsa240-4.9-0001-x86-limit-linear-page-table-use-to-a-single-level.patch494
-rw-r--r--system/xen/xsa/xsa240-4.9-0002-x86-mm-Disable-PV-linear-pagetables-by-default.patch83
-rw-r--r--system/xen/xsa/xsa241-4.9.patch120
-rw-r--r--system/xen/xsa/xsa242-4.9.patch43
-rw-r--r--system/xen/xsa/xsa243.patch93
-rw-r--r--system/xen/xsa/xsa244.patch59
-rw-r--r--system/xen/xsa/xsa245-0001-xen-page_alloc-Cover-memory-unreserved-after-boot-in.patch48
-rw-r--r--system/xen/xsa/xsa245-0002-xen-arm-Correctly-report-the-memory-region-in-the-du.patch73
16 files changed, 1414 insertions, 1 deletions
diff --git a/system/xen/xen.SlackBuild b/system/xen/xen.SlackBuild
index 8b56171fbd..4405bf7284 100644
--- a/system/xen/xen.SlackBuild
+++ b/system/xen/xen.SlackBuild
@@ -24,7 +24,7 @@
PRGNAM=xen
VERSION=${VERSION:-4.9.0}
-BUILD=${BUILD:-3}
+BUILD=${BUILD:-4}
TAG=${TAG:-_SBo}
SEABIOS=${SEABIOS:-1.10.0}
diff --git a/system/xen/xsa/xsa237-4.9-0001-x86-dont-allow-MSI-pIRQ-mapping-on-unowned-device.patch b/system/xen/xsa/xsa237-4.9-0001-x86-dont-allow-MSI-pIRQ-mapping-on-unowned-device.patch
new file mode 100644
index 0000000000..7c9dff9672
--- /dev/null
+++ b/system/xen/xsa/xsa237-4.9-0001-x86-dont-allow-MSI-pIRQ-mapping-on-unowned-device.patch
@@ -0,0 +1,27 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86: don't allow MSI pIRQ mapping on unowned device
+
+MSI setup should be permitted only for existing devices owned by the
+respective guest (the operation may still be carried out by the domain
+controlling that guest).
+
+This is part of XSA-237.
+
+Reported-by: HW42 <hw42@ipsumj.de>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
+
+--- a/xen/arch/x86/irq.c
++++ b/xen/arch/x86/irq.c
+@@ -1963,7 +1963,10 @@ int map_domain_pirq(
+ if ( !cpu_has_apic )
+ goto done;
+
+- pdev = pci_get_pdev(msi->seg, msi->bus, msi->devfn);
++ pdev = pci_get_pdev_by_domain(d, msi->seg, msi->bus, msi->devfn);
++ if ( !pdev )
++ goto done;
++
+ ret = pci_enable_msi(msi, &msi_desc);
+ if ( ret )
+ {
diff --git a/system/xen/xsa/xsa237-4.9-0002-x86-enforce-proper-privilege-when-mapping-pIRQ-s.patch b/system/xen/xsa/xsa237-4.9-0002-x86-enforce-proper-privilege-when-mapping-pIRQ-s.patch
new file mode 100644
index 0000000000..0add704587
--- /dev/null
+++ b/system/xen/xsa/xsa237-4.9-0002-x86-enforce-proper-privilege-when-mapping-pIRQ-s.patch
@@ -0,0 +1,66 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86: enforce proper privilege when (un)mapping pIRQ-s
+
+(Un)mapping of IRQs, just like other RESOURCE__ADD* / RESOURCE__REMOVE*
+actions (in FLASK terms) should be XSM_DM_PRIV rather than XSM_TARGET.
+This in turn requires bypassing the XSM check in physdev_unmap_pirq()
+for the HVM emuirq case just like is being done in physdev_map_pirq().
+The primary goal security wise, however, is to no longer allow HVM
+guests, by specifying their own domain ID instead of DOMID_SELF, to
+enter code paths intended for PV guest and the control domains of HVM
+guests only.
+
+This is part of XSA-237.
+
+Reported-by: HW42 <hw42@ipsumj.de>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: George Dunlap <george.dunlap@citrix.com>
+
+--- a/xen/arch/x86/physdev.c
++++ b/xen/arch/x86/physdev.c
+@@ -111,7 +111,7 @@ int physdev_map_pirq(domid_t domid, int
+ if ( d == NULL )
+ return -ESRCH;
+
+- ret = xsm_map_domain_pirq(XSM_TARGET, d);
++ ret = xsm_map_domain_pirq(XSM_DM_PRIV, d);
+ if ( ret )
+ goto free_domain;
+
+@@ -256,13 +256,14 @@ int physdev_map_pirq(domid_t domid, int
+ int physdev_unmap_pirq(domid_t domid, int pirq)
+ {
+ struct domain *d;
+- int ret;
++ int ret = 0;
+
+ d = rcu_lock_domain_by_any_id(domid);
+ if ( d == NULL )
+ return -ESRCH;
+
+- ret = xsm_unmap_domain_pirq(XSM_TARGET, d);
++ if ( domid != DOMID_SELF || !is_hvm_domain(d) || !has_pirq(d) )
++ ret = xsm_unmap_domain_pirq(XSM_DM_PRIV, d);
+ if ( ret )
+ goto free_domain;
+
+--- a/xen/include/xsm/dummy.h
++++ b/xen/include/xsm/dummy.h
+@@ -453,7 +453,7 @@ static XSM_INLINE char *xsm_show_irq_sid
+
+ static XSM_INLINE int xsm_map_domain_pirq(XSM_DEFAULT_ARG struct domain *d)
+ {
+- XSM_ASSERT_ACTION(XSM_TARGET);
++ XSM_ASSERT_ACTION(XSM_DM_PRIV);
+ return xsm_default_action(action, current->domain, d);
+ }
+
+@@ -465,7 +465,7 @@ static XSM_INLINE int xsm_map_domain_irq
+
+ static XSM_INLINE int xsm_unmap_domain_pirq(XSM_DEFAULT_ARG struct domain *d)
+ {
+- XSM_ASSERT_ACTION(XSM_TARGET);
++ XSM_ASSERT_ACTION(XSM_DM_PRIV);
+ return xsm_default_action(action, current->domain, d);
+ }
+
diff --git a/system/xen/xsa/xsa237-4.9-0003-x86-MSI-disallow-redundant-enabling.patch b/system/xen/xsa/xsa237-4.9-0003-x86-MSI-disallow-redundant-enabling.patch
new file mode 100644
index 0000000000..5c69c48265
--- /dev/null
+++ b/system/xen/xsa/xsa237-4.9-0003-x86-MSI-disallow-redundant-enabling.patch
@@ -0,0 +1,55 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86/MSI: disallow redundant enabling
+
+At the moment, Xen attempts to allow redundant enabling of MSI by
+having pci_enable_msi() return 0, and point to the existing MSI
+descriptor, when the msi already exists.
+
+Unfortunately, if subsequent errors are encountered, the cleanup
+paths assume pci_enable_msi() had done full initialization, and
+hence undo everything that was assumed to be done by that
+function without also undoing other setup that would normally
+occur only after that function was called (in map_domain_pirq()
+itself).
+
+Rather than try to make the redundant enabling case work properly, just
+forbid it entirely by having pci_enable_msi() return -EEXIST when MSI
+is already set up.
+
+This is part of XSA-237.
+
+Reported-by: HW42 <hw42@ipsumj.de>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
+Reviewed-by: George Dunlap <george.dunlap@citrix.com>
+
+--- a/xen/arch/x86/msi.c
++++ b/xen/arch/x86/msi.c
+@@ -1050,11 +1050,10 @@ static int __pci_enable_msi(struct msi_i
+ old_desc = find_msi_entry(pdev, msi->irq, PCI_CAP_ID_MSI);
+ if ( old_desc )
+ {
+- printk(XENLOG_WARNING "irq %d already mapped to MSI on %04x:%02x:%02x.%u\n",
++ printk(XENLOG_ERR "irq %d already mapped to MSI on %04x:%02x:%02x.%u\n",
+ msi->irq, msi->seg, msi->bus,
+ PCI_SLOT(msi->devfn), PCI_FUNC(msi->devfn));
+- *desc = old_desc;
+- return 0;
++ return -EEXIST;
+ }
+
+ old_desc = find_msi_entry(pdev, -1, PCI_CAP_ID_MSIX);
+@@ -1118,11 +1117,10 @@ static int __pci_enable_msix(struct msi_
+ old_desc = find_msi_entry(pdev, msi->irq, PCI_CAP_ID_MSIX);
+ if ( old_desc )
+ {
+- printk(XENLOG_WARNING "irq %d already mapped to MSI-X on %04x:%02x:%02x.%u\n",
++ printk(XENLOG_ERR "irq %d already mapped to MSI-X on %04x:%02x:%02x.%u\n",
+ msi->irq, msi->seg, msi->bus,
+ PCI_SLOT(msi->devfn), PCI_FUNC(msi->devfn));
+- *desc = old_desc;
+- return 0;
++ return -EEXIST;
+ }
+
+ old_desc = find_msi_entry(pdev, -1, PCI_CAP_ID_MSI);
diff --git a/system/xen/xsa/xsa237-4.9-0004-x86-IRQ-conditionally-preserve-irq-pirq-mapping-on-error.patch b/system/xen/xsa/xsa237-4.9-0004-x86-IRQ-conditionally-preserve-irq-pirq-mapping-on-error.patch
new file mode 100644
index 0000000000..a16ec1bba1
--- /dev/null
+++ b/system/xen/xsa/xsa237-4.9-0004-x86-IRQ-conditionally-preserve-irq-pirq-mapping-on-error.patch
@@ -0,0 +1,124 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86/IRQ: conditionally preserve irq <-> pirq mapping on map error paths
+
+Mappings that had been set up before should not be torn down when
+handling unrelated errors.
+
+This is part of XSA-237.
+
+Reported-by: HW42 <hw42@ipsumj.de>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: George Dunlap <george.dunlap@citrix.com>
+
+--- a/xen/arch/x86/irq.c
++++ b/xen/arch/x86/irq.c
+@@ -1251,7 +1251,8 @@ static int prepare_domain_irq_pirq(struc
+ return -ENOMEM;
+ }
+ *pinfo = info;
+- return 0;
++
++ return !!err;
+ }
+
+ static void set_domain_irq_pirq(struct domain *d, int irq, struct pirq *pirq)
+@@ -1294,7 +1295,10 @@ int init_domain_irq_mapping(struct domai
+ continue;
+ err = prepare_domain_irq_pirq(d, i, i, &info);
+ if ( err )
++ {
++ ASSERT(err < 0);
+ break;
++ }
+ set_domain_irq_pirq(d, i, info);
+ }
+
+@@ -1902,6 +1906,7 @@ int map_domain_pirq(
+ struct pirq *info;
+ struct irq_desc *desc;
+ unsigned long flags;
++ DECLARE_BITMAP(prepared, MAX_MSI_IRQS) = {};
+
+ ASSERT(spin_is_locked(&d->event_lock));
+
+@@ -1945,8 +1950,10 @@ int map_domain_pirq(
+ }
+
+ ret = prepare_domain_irq_pirq(d, irq, pirq, &info);
+- if ( ret )
++ if ( ret < 0 )
+ goto revoke;
++ if ( !ret )
++ __set_bit(0, prepared);
+
+ desc = irq_to_desc(irq);
+
+@@ -2018,8 +2025,10 @@ int map_domain_pirq(
+ irq = create_irq(NUMA_NO_NODE);
+ ret = irq >= 0 ? prepare_domain_irq_pirq(d, irq, pirq + nr, &info)
+ : irq;
+- if ( ret )
++ if ( ret < 0 )
+ break;
++ if ( !ret )
++ __set_bit(nr, prepared);
+ msi_desc[nr].irq = irq;
+
+ if ( irq_permit_access(d, irq) != 0 )
+@@ -2052,15 +2061,15 @@ int map_domain_pirq(
+ desc->msi_desc = NULL;
+ spin_unlock_irqrestore(&desc->lock, flags);
+ }
+- while ( nr-- )
++ while ( nr )
+ {
+ if ( irq >= 0 && irq_deny_access(d, irq) )
+ printk(XENLOG_G_ERR
+ "dom%d: could not revoke access to IRQ%d (pirq %d)\n",
+ d->domain_id, irq, pirq);
+- if ( info )
++ if ( info && test_bit(nr, prepared) )
+ cleanup_domain_irq_pirq(d, irq, info);
+- info = pirq_info(d, pirq + nr);
++ info = pirq_info(d, pirq + --nr);
+ irq = info->arch.irq;
+ }
+ msi_desc->irq = -1;
+@@ -2076,12 +2085,14 @@ int map_domain_pirq(
+ spin_lock_irqsave(&desc->lock, flags);
+ set_domain_irq_pirq(d, irq, info);
+ spin_unlock_irqrestore(&desc->lock, flags);
++ ret = 0;
+ }
+
+ done:
+ if ( ret )
+ {
+- cleanup_domain_irq_pirq(d, irq, info);
++ if ( test_bit(0, prepared) )
++ cleanup_domain_irq_pirq(d, irq, info);
+ revoke:
+ if ( irq_deny_access(d, irq) )
+ printk(XENLOG_G_ERR
+--- a/xen/arch/x86/physdev.c
++++ b/xen/arch/x86/physdev.c
+@@ -186,7 +186,7 @@ int physdev_map_pirq(domid_t domid, int
+ }
+ else if ( type == MAP_PIRQ_TYPE_MULTI_MSI )
+ {
+- if ( msi->entry_nr <= 0 || msi->entry_nr > 32 )
++ if ( msi->entry_nr <= 0 || msi->entry_nr > MAX_MSI_IRQS )
+ ret = -EDOM;
+ else if ( msi->entry_nr != 1 && !iommu_intremap )
+ ret = -EOPNOTSUPP;
+--- a/xen/include/asm-x86/msi.h
++++ b/xen/include/asm-x86/msi.h
+@@ -56,6 +56,8 @@
+ /* MAX fixed pages reserved for mapping MSIX tables. */
+ #define FIX_MSIX_MAX_PAGES 512
+
++#define MAX_MSI_IRQS 32 /* limited by MSI capability struct properties */
++
+ struct msi_info {
+ u16 seg;
+ u8 bus;
diff --git a/system/xen/xsa/xsa237-4.9-0005-x86-FLASK-fix-unmap-domain-IRQ-XSM-hook.patch b/system/xen/xsa/xsa237-4.9-0005-x86-FLASK-fix-unmap-domain-IRQ-XSM-hook.patch
new file mode 100644
index 0000000000..155ba15d08
--- /dev/null
+++ b/system/xen/xsa/xsa237-4.9-0005-x86-FLASK-fix-unmap-domain-IRQ-XSM-hook.patch
@@ -0,0 +1,37 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86/FLASK: fix unmap-domain-IRQ XSM hook
+
+The caller and the FLASK implementation of xsm_unmap_domain_irq()
+disagreed about what the "data" argument points to in the MSI case:
+Change both sides to pass/take a PCI device.
+
+This is part of XSA-237.
+
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
+
+--- a/xen/arch/x86/irq.c
++++ b/xen/arch/x86/irq.c
+@@ -2143,7 +2143,8 @@ int unmap_domain_pirq(struct domain *d,
+ nr = msi_desc->msi.nvec;
+ }
+
+- ret = xsm_unmap_domain_irq(XSM_HOOK, d, irq, msi_desc);
++ ret = xsm_unmap_domain_irq(XSM_HOOK, d, irq,
++ msi_desc ? msi_desc->dev : NULL);
+ if ( ret )
+ goto done;
+
+--- a/xen/xsm/flask/hooks.c
++++ b/xen/xsm/flask/hooks.c
+@@ -918,8 +918,8 @@ static int flask_unmap_domain_msi (struc
+ u32 *sid, struct avc_audit_data *ad)
+ {
+ #ifdef CONFIG_HAS_PCI
+- struct msi_info *msi = data;
+- u32 machine_bdf = (msi->seg << 16) | (msi->bus << 8) | msi->devfn;
++ const struct pci_dev *pdev = data;
++ u32 machine_bdf = (pdev->seg << 16) | (pdev->bus << 8) | pdev->devfn;
+
+ AVC_AUDIT_DATA_INIT(ad, DEV);
+ ad->device = machine_bdf;
diff --git a/system/xen/xsa/xsa238.patch b/system/xen/xsa/xsa238.patch
new file mode 100644
index 0000000000..0d7d48fef8
--- /dev/null
+++ b/system/xen/xsa/xsa238.patch
@@ -0,0 +1,45 @@
+From cdc2887076b19b39fab9faec495082586f3113df Mon Sep 17 00:00:00 2001
+From: XenProject Security Team <security@xenproject.org>
+Date: Tue, 5 Sep 2017 13:41:37 +0200
+Subject: x86/ioreq server: correctly handle bogus
+ XEN_DMOP_{,un}map_io_range_to_ioreq_server arguments
+
+Misbehaving device model can pass incorrect XEN_DMOP_map/
+unmap_io_range_to_ioreq_server arguments, namely end < start when
+specifying address range. When this happens we hit ASSERT(s <= e) in
+rangeset_contains_range()/rangeset_overlaps_range() with debug builds.
+Production builds will not trap right away but may misbehave later
+while handling such bogus ranges.
+
+This is XSA-238.
+
+Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
+Reviewed-by: Jan Beulich <jbeulich@suse.com>
+---
+ xen/arch/x86/hvm/ioreq.c | 6 ++++++
+ 1 file changed, 6 insertions(+)
+
+diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c
+index b2a8b0e986..8c8bf1f0ec 100644
+--- a/xen/arch/x86/hvm/ioreq.c
++++ b/xen/arch/x86/hvm/ioreq.c
+@@ -820,6 +820,9 @@ int hvm_map_io_range_to_ioreq_server(struct domain *d, ioservid_t id,
+ struct hvm_ioreq_server *s;
+ int rc;
+
++ if ( start > end )
++ return -EINVAL;
++
+ spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock);
+
+ rc = -ENOENT;
+@@ -872,6 +875,9 @@ int hvm_unmap_io_range_from_ioreq_server(struct domain *d, ioservid_t id,
+ struct hvm_ioreq_server *s;
+ int rc;
+
++ if ( start > end )
++ return -EINVAL;
++
+ spin_lock_recursive(&d->arch.hvm_domain.ioreq_server.lock);
+
+ rc = -ENOENT;
diff --git a/system/xen/xsa/xsa239.patch b/system/xen/xsa/xsa239.patch
new file mode 100644
index 0000000000..5daecb5e47
--- /dev/null
+++ b/system/xen/xsa/xsa239.patch
@@ -0,0 +1,46 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86/HVM: prefill partially used variable on emulation paths
+
+Certain handlers ignore the access size (vioapic_write() being the
+example this was found with), perhaps leading to subsequent reads
+seeing data that wasn't actually written by the guest. For
+consistency and extra safety also do this on the read path of
+hvm_process_io_intercept(), even if this doesn't directly affect what
+guests get to see, as we've supposedly already dealt with read handlers
+leaving data completely unitialized.
+
+This is XSA-239.
+
+Reported-by: Roger Pau Monné <roger.pau@citrix.com>
+Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+
+--- a/xen/arch/x86/hvm/emulate.c
++++ b/xen/arch/x86/hvm/emulate.c
+@@ -129,7 +129,7 @@ static int hvmemul_do_io(
+ .count = *reps,
+ .dir = dir,
+ .df = df,
+- .data = data,
++ .data = data_is_addr ? data : 0,
+ .data_is_ptr = data_is_addr, /* ioreq_t field name is misleading */
+ .state = STATE_IOREQ_READY,
+ };
+--- a/xen/arch/x86/hvm/intercept.c
++++ b/xen/arch/x86/hvm/intercept.c
+@@ -127,6 +127,7 @@ int hvm_process_io_intercept(const struc
+ addr = (p->type == IOREQ_TYPE_COPY) ?
+ p->addr + step * i :
+ p->addr;
++ data = 0;
+ rc = ops->read(handler, addr, p->size, &data);
+ if ( rc != X86EMUL_OKAY )
+ break;
+@@ -161,6 +162,7 @@ int hvm_process_io_intercept(const struc
+ {
+ if ( p->data_is_ptr )
+ {
++ data = 0;
+ switch ( hvm_copy_from_guest_phys(&data, p->data + step * i,
+ p->size) )
+ {
diff --git a/system/xen/xsa/xsa240-4.9-0001-x86-limit-linear-page-table-use-to-a-single-level.patch b/system/xen/xsa/xsa240-4.9-0001-x86-limit-linear-page-table-use-to-a-single-level.patch
new file mode 100644
index 0000000000..515ad22b66
--- /dev/null
+++ b/system/xen/xsa/xsa240-4.9-0001-x86-limit-linear-page-table-use-to-a-single-level.patch
@@ -0,0 +1,494 @@
+From 867988237d3e472fe2c99e81ae733e103422566c Mon Sep 17 00:00:00 2001
+From: Jan Beulich <jbeulich@suse.com>
+Date: Thu, 28 Sep 2017 15:17:25 +0100
+Subject: [PATCH 1/2] x86: limit linear page table use to a single level
+
+That's the only way that they're meant to be used. Without such a
+restriction arbitrarily long chains of same-level page tables can be
+built, tearing down of which may then cause arbitrarily deep recursion,
+causing a stack overflow. To facilitate this restriction, a counter is
+being introduced to track both the number of same-level entries in a
+page table as well as the number of uses of a page table in another
+same-level one (counting into positive and negative direction
+respectively, utilizing the fact that both counts can't be non-zero at
+the same time).
+
+Note that the added accounting introduces a restriction on the number
+of times a page can be used in other same-level page tables - more than
+32k of such uses are no longer possible.
+
+Note also that some put_page_and_type[_preemptible]() calls are
+replaced with open-coded equivalents. This seemed preferrable to
+adding "parent_table" to the matrix of functions.
+
+Note further that cross-domain same-level page table references are no
+longer permitted (they probably never should have been).
+
+This is XSA-240.
+
+Reported-by: Jann Horn <jannh@google.com>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Signed-off-by: George Dunlap <george.dunlap@citrix.com>
+---
+ xen/arch/x86/domain.c | 1 +
+ xen/arch/x86/mm.c | 171 ++++++++++++++++++++++++++++++++++++++-----
+ xen/include/asm-x86/domain.h | 2 +
+ xen/include/asm-x86/mm.h | 25 +++++--
+ 4 files changed, 175 insertions(+), 24 deletions(-)
+
+diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
+index d7e699228c..d7ed72c246 100644
+--- a/xen/arch/x86/domain.c
++++ b/xen/arch/x86/domain.c
+@@ -1226,6 +1226,7 @@ int arch_set_info_guest(
+ rc = -ERESTART;
+ /* Fallthrough */
+ case -ERESTART:
++ v->arch.old_guest_ptpg = NULL;
+ v->arch.old_guest_table =
+ pagetable_get_page(v->arch.guest_table);
+ v->arch.guest_table = pagetable_null();
+diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
+index 86f5eda52d..1e469bd354 100644
+--- a/xen/arch/x86/mm.c
++++ b/xen/arch/x86/mm.c
+@@ -747,6 +747,61 @@ static void put_data_page(
+ put_page(page);
+ }
+
++static bool inc_linear_entries(struct page_info *pg)
++{
++ typeof(pg->linear_pt_count) nc = read_atomic(&pg->linear_pt_count), oc;
++
++ do {
++ /*
++ * The check below checks for the "linear use" count being non-zero
++ * as well as overflow. Signed integer overflow is undefined behavior
++ * according to the C spec. However, as long as linear_pt_count is
++ * smaller in size than 'int', the arithmetic operation of the
++ * increment below won't overflow; rather the result will be truncated
++ * when stored. Ensure that this is always true.
++ */
++ BUILD_BUG_ON(sizeof(nc) >= sizeof(int));
++ oc = nc++;
++ if ( nc <= 0 )
++ return false;
++ nc = cmpxchg(&pg->linear_pt_count, oc, nc);
++ } while ( oc != nc );
++
++ return true;
++}
++
++static void dec_linear_entries(struct page_info *pg)
++{
++ typeof(pg->linear_pt_count) oc;
++
++ oc = arch_fetch_and_add(&pg->linear_pt_count, -1);
++ ASSERT(oc > 0);
++}
++
++static bool inc_linear_uses(struct page_info *pg)
++{
++ typeof(pg->linear_pt_count) nc = read_atomic(&pg->linear_pt_count), oc;
++
++ do {
++ /* See the respective comment in inc_linear_entries(). */
++ BUILD_BUG_ON(sizeof(nc) >= sizeof(int));
++ oc = nc--;
++ if ( nc >= 0 )
++ return false;
++ nc = cmpxchg(&pg->linear_pt_count, oc, nc);
++ } while ( oc != nc );
++
++ return true;
++}
++
++static void dec_linear_uses(struct page_info *pg)
++{
++ typeof(pg->linear_pt_count) oc;
++
++ oc = arch_fetch_and_add(&pg->linear_pt_count, 1);
++ ASSERT(oc < 0);
++}
++
+ /*
+ * We allow root tables to map each other (a.k.a. linear page tables). It
+ * needs some special care with reference counts and access permissions:
+@@ -777,15 +832,35 @@ get_##level##_linear_pagetable( \
+ \
+ if ( (pfn = level##e_get_pfn(pde)) != pde_pfn ) \
+ { \
++ struct page_info *ptpg = mfn_to_page(pde_pfn); \
++ \
++ /* Make sure the page table belongs to the correct domain. */ \
++ if ( unlikely(page_get_owner(ptpg) != d) ) \
++ return 0; \
++ \
+ /* Make sure the mapped frame belongs to the correct domain. */ \
+ if ( unlikely(!get_page_from_pagenr(pfn, d)) ) \
+ return 0; \
+ \
+ /* \
+- * Ensure that the mapped frame is an already-validated page table. \
++ * Ensure that the mapped frame is an already-validated page table \
++ * and is not itself having linear entries, as well as that the \
++ * containing page table is not iself in use as a linear page table \
++ * elsewhere. \
+ * If so, atomically increment the count (checking for overflow). \
+ */ \
+ page = mfn_to_page(pfn); \
++ if ( !inc_linear_entries(ptpg) ) \
++ { \
++ put_page(page); \
++ return 0; \
++ } \
++ if ( !inc_linear_uses(page) ) \
++ { \
++ dec_linear_entries(ptpg); \
++ put_page(page); \
++ return 0; \
++ } \
+ y = page->u.inuse.type_info; \
+ do { \
+ x = y; \
+@@ -793,6 +868,8 @@ get_##level##_linear_pagetable( \
+ unlikely((x & (PGT_type_mask|PGT_validated)) != \
+ (PGT_##level##_page_table|PGT_validated)) ) \
+ { \
++ dec_linear_uses(page); \
++ dec_linear_entries(ptpg); \
+ put_page(page); \
+ return 0; \
+ } \
+@@ -1226,6 +1303,9 @@ get_page_from_l4e(
+ l3e_remove_flags((pl3e), _PAGE_USER|_PAGE_RW|_PAGE_ACCESSED); \
+ } while ( 0 )
+
++static int _put_page_type(struct page_info *page, bool preemptible,
++ struct page_info *ptpg);
++
+ void put_page_from_l1e(l1_pgentry_t l1e, struct domain *l1e_owner)
+ {
+ unsigned long pfn = l1e_get_pfn(l1e);
+@@ -1296,17 +1376,22 @@ static int put_page_from_l2e(l2_pgentry_t l2e, unsigned long pfn)
+ if ( l2e_get_flags(l2e) & _PAGE_PSE )
+ put_superpage(l2e_get_pfn(l2e));
+ else
+- put_page_and_type(l2e_get_page(l2e));
++ {
++ struct page_info *pg = l2e_get_page(l2e);
++ int rc = _put_page_type(pg, false, mfn_to_page(pfn));
++
++ ASSERT(!rc);
++ put_page(pg);
++ }
+
+ return 0;
+ }
+
+-static int __put_page_type(struct page_info *, int preemptible);
+-
+ static int put_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn,
+ int partial, bool_t defer)
+ {
+ struct page_info *pg;
++ int rc;
+
+ if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) || (l3e_get_pfn(l3e) == pfn) )
+ return 1;
+@@ -1329,21 +1414,28 @@ static int put_page_from_l3e(l3_pgentry_t l3e, unsigned long pfn,
+ if ( unlikely(partial > 0) )
+ {
+ ASSERT(!defer);
+- return __put_page_type(pg, 1);
++ return _put_page_type(pg, true, mfn_to_page(pfn));
+ }
+
+ if ( defer )
+ {
++ current->arch.old_guest_ptpg = mfn_to_page(pfn);
+ current->arch.old_guest_table = pg;
+ return 0;
+ }
+
+- return put_page_and_type_preemptible(pg);
++ rc = _put_page_type(pg, true, mfn_to_page(pfn));
++ if ( likely(!rc) )
++ put_page(pg);
++
++ return rc;
+ }
+
+ static int put_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn,
+ int partial, bool_t defer)
+ {
++ int rc = 1;
++
+ if ( (l4e_get_flags(l4e) & _PAGE_PRESENT) &&
+ (l4e_get_pfn(l4e) != pfn) )
+ {
+@@ -1352,18 +1444,22 @@ static int put_page_from_l4e(l4_pgentry_t l4e, unsigned long pfn,
+ if ( unlikely(partial > 0) )
+ {
+ ASSERT(!defer);
+- return __put_page_type(pg, 1);
++ return _put_page_type(pg, true, mfn_to_page(pfn));
+ }
+
+ if ( defer )
+ {
++ current->arch.old_guest_ptpg = mfn_to_page(pfn);
+ current->arch.old_guest_table = pg;
+ return 0;
+ }
+
+- return put_page_and_type_preemptible(pg);
++ rc = _put_page_type(pg, true, mfn_to_page(pfn));
++ if ( likely(!rc) )
++ put_page(pg);
+ }
+- return 1;
++
++ return rc;
+ }
+
+ static int alloc_l1_table(struct page_info *page)
+@@ -1561,6 +1657,7 @@ static int alloc_l3_table(struct page_info *page)
+ {
+ page->nr_validated_ptes = i;
+ page->partial_pte = 0;
++ current->arch.old_guest_ptpg = NULL;
+ current->arch.old_guest_table = page;
+ }
+ while ( i-- > 0 )
+@@ -1654,6 +1751,7 @@ static int alloc_l4_table(struct page_info *page)
+ {
+ if ( current->arch.old_guest_table )
+ page->nr_validated_ptes++;
++ current->arch.old_guest_ptpg = NULL;
+ current->arch.old_guest_table = page;
+ }
+ }
+@@ -2403,14 +2501,20 @@ int free_page_type(struct page_info *pag
+ }
+
+
+-static int __put_final_page_type(
+- struct page_info *page, unsigned long type, int preemptible)
++static int _put_final_page_type(struct page_info *page, unsigned long type,
++ bool preemptible, struct page_info *ptpg)
+ {
+ int rc = free_page_type(page, type, preemptible);
+
+ /* No need for atomic update of type_info here: noone else updates it. */
+ if ( rc == 0 )
+ {
++ if ( ptpg && PGT_type_equal(type, ptpg->u.inuse.type_info) )
++ {
++ dec_linear_uses(page);
++ dec_linear_entries(ptpg);
++ }
++ ASSERT(!page->linear_pt_count || page_get_owner(page)->is_dying);
+ /*
+ * Record TLB information for flush later. We do not stamp page tables
+ * when running in shadow mode:
+@@ -2446,8 +2550,8 @@ static int __put_final_page_type(
+ }
+
+
+-static int __put_page_type(struct page_info *page,
+- int preemptible)
++static int _put_page_type(struct page_info *page, bool preemptible,
++ struct page_info *ptpg)
+ {
+ unsigned long nx, x, y = page->u.inuse.type_info;
+ int rc = 0;
+@@ -2474,12 +2578,28 @@ static int __put_page_type(struct page_info *page,
+ x, nx)) != x) )
+ continue;
+ /* We cleared the 'valid bit' so we do the clean up. */
+- rc = __put_final_page_type(page, x, preemptible);
++ rc = _put_final_page_type(page, x, preemptible, ptpg);
++ ptpg = NULL;
+ if ( x & PGT_partial )
+ put_page(page);
+ break;
+ }
+
++ if ( ptpg && PGT_type_equal(x, ptpg->u.inuse.type_info) )
++ {
++ /*
++ * page_set_tlbflush_timestamp() accesses the same union
++ * linear_pt_count lives in. Unvalidated page table pages,
++ * however, should occur during domain destruction only
++ * anyway. Updating of linear_pt_count luckily is not
++ * necessary anymore for a dying domain.
++ */
++ ASSERT(page_get_owner(page)->is_dying);
++ ASSERT(page->linear_pt_count < 0);
++ ASSERT(ptpg->linear_pt_count > 0);
++ ptpg = NULL;
++ }
++
+ /*
+ * Record TLB information for flush later. We do not stamp page
+ * tables when running in shadow mode:
+@@ -2499,6 +2619,13 @@ static int __put_page_type(struct page_info *page,
+ return -EINTR;
+ }
+
++ if ( ptpg && PGT_type_equal(x, ptpg->u.inuse.type_info) )
++ {
++ ASSERT(!rc);
++ dec_linear_uses(page);
++ dec_linear_entries(ptpg);
++ }
++
+ return rc;
+ }
+
+@@ -2638,6 +2765,7 @@ static int __get_page_type(struct page_info *page, unsigned long type,
+ page->nr_validated_ptes = 0;
+ page->partial_pte = 0;
+ }
++ page->linear_pt_count = 0;
+ rc = alloc_page_type(page, type, preemptible);
+ }
+
+@@ -2652,7 +2780,7 @@ static int __get_page_type(struct page_info *page, unsigned long type,
+
+ void put_page_type(struct page_info *page)
+ {
+- int rc = __put_page_type(page, 0);
++ int rc = _put_page_type(page, false, NULL);
+ ASSERT(rc == 0);
+ (void)rc;
+ }
+@@ -2668,7 +2796,7 @@ int get_page_type(struct page_info *page, unsigned long type)
+
+ int put_page_type_preemptible(struct page_info *page)
+ {
+- return __put_page_type(page, 1);
++ return _put_page_type(page, true, NULL);
+ }
+
+ int get_page_type_preemptible(struct page_info *page, unsigned long type)
+@@ -2878,11 +3006,14 @@ int put_old_guest_table(struct vcpu *v)
+ if ( !v->arch.old_guest_table )
+ return 0;
+
+- switch ( rc = put_page_and_type_preemptible(v->arch.old_guest_table) )
++ switch ( rc = _put_page_type(v->arch.old_guest_table, true,
++ v->arch.old_guest_ptpg) )
+ {
+ case -EINTR:
+ case -ERESTART:
+ return -ERESTART;
++ case 0:
++ put_page(v->arch.old_guest_table);
+ }
+
+ v->arch.old_guest_table = NULL;
+@@ -3042,6 +3173,7 @@ int new_guest_cr3(unsigned long mfn)
+ rc = -ERESTART;
+ /* fallthrough */
+ case -ERESTART:
++ curr->arch.old_guest_ptpg = NULL;
+ curr->arch.old_guest_table = page;
+ break;
+ default:
+@@ -3310,7 +3442,10 @@ long do_mmuext_op(
+ if ( type == PGT_l1_page_table )
+ put_page_and_type(page);
+ else
++ {
++ curr->arch.old_guest_ptpg = NULL;
+ curr->arch.old_guest_table = page;
++ }
+ }
+ }
+
+@@ -3346,6 +3481,7 @@ long do_mmuext_op(
+ {
+ case -EINTR:
+ case -ERESTART:
++ curr->arch.old_guest_ptpg = NULL;
+ curr->arch.old_guest_table = page;
+ rc = 0;
+ break;
+@@ -3425,6 +3561,7 @@ long do_mmuext_op(
+ rc = -ERESTART;
+ /* fallthrough */
+ case -ERESTART:
++ curr->arch.old_guest_ptpg = NULL;
+ curr->arch.old_guest_table = page;
+ break;
+ default:
+diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
+index 924caac834..5a512918cc 100644
+--- a/xen/include/asm-x86/domain.h
++++ b/xen/include/asm-x86/domain.h
+@@ -527,6 +527,8 @@ struct arch_vcpu
+ pagetable_t guest_table_user; /* (MFN) x86/64 user-space pagetable */
+ pagetable_t guest_table; /* (MFN) guest notion of cr3 */
+ struct page_info *old_guest_table; /* partially destructed pagetable */
++ struct page_info *old_guest_ptpg; /* containing page table of the */
++ /* former, if any */
+ /* guest_table holds a ref to the page, and also a type-count unless
+ * shadow refcounts are in use */
+ pagetable_t shadow_table[4]; /* (MFN) shadow(s) of guest */
+diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
+index 119d7dec6b..445da50d47 100644
+--- a/xen/include/asm-x86/mm.h
++++ b/xen/include/asm-x86/mm.h
+@@ -124,11 +124,11 @@ struct page_info
+ u32 tlbflush_timestamp;
+
+ /*
+- * When PGT_partial is true then this field is valid and indicates
+- * that PTEs in the range [0, @nr_validated_ptes) have been validated.
+- * An extra page reference must be acquired (or not dropped) whenever
+- * PGT_partial gets set, and it must be dropped when the flag gets
+- * cleared. This is so that a get() leaving a page in partially
++ * When PGT_partial is true then the first two fields are valid and
++ * indicate that PTEs in the range [0, @nr_validated_ptes) have been
++ * validated. An extra page reference must be acquired (or not dropped)
++ * whenever PGT_partial gets set, and it must be dropped when the flag
++ * gets cleared. This is so that a get() leaving a page in partially
+ * validated state (where the caller would drop the reference acquired
+ * due to the getting of the type [apparently] failing [-ERESTART])
+ * would not accidentally result in a page left with zero general
+@@ -152,10 +152,18 @@ struct page_info
+ * put_page_from_lNe() (due to the apparent failure), and hence it
+ * must be dropped when the put operation is resumed (and completes),
+ * but it must not be acquired if picking up the page for validation.
++ *
++ * The 3rd field, @linear_pt_count, indicates
++ * - by a positive value, how many same-level page table entries a page
++ * table has,
++ * - by a negative value, in how many same-level page tables a page is
++ * in use.
+ */
+ struct {
+- u16 nr_validated_ptes;
+- s8 partial_pte;
++ u16 nr_validated_ptes:PAGETABLE_ORDER + 1;
++ u16 :16 - PAGETABLE_ORDER - 1 - 2;
++ s16 partial_pte:2;
++ s16 linear_pt_count;
+ };
+
+ /*
+@@ -206,6 +214,9 @@ struct page_info
+ #define PGT_count_width PG_shift(9)
+ #define PGT_count_mask ((1UL<<PGT_count_width)-1)
+
++/* Are the 'type mask' bits identical? */
++#define PGT_type_equal(x, y) (!(((x) ^ (y)) & PGT_type_mask))
++
+ /* Cleared when the owning guest 'frees' this page. */
+ #define _PGC_allocated PG_shift(1)
+ #define PGC_allocated PG_mask(1, 1)
+--
+2.14.1
+
diff --git a/system/xen/xsa/xsa240-4.9-0002-x86-mm-Disable-PV-linear-pagetables-by-default.patch b/system/xen/xsa/xsa240-4.9-0002-x86-mm-Disable-PV-linear-pagetables-by-default.patch
new file mode 100644
index 0000000000..5e057c5652
--- /dev/null
+++ b/system/xen/xsa/xsa240-4.9-0002-x86-mm-Disable-PV-linear-pagetables-by-default.patch
@@ -0,0 +1,83 @@
+From e614979ce054044d9e19023f1ef10dae6e38baf4 Mon Sep 17 00:00:00 2001
+From: George Dunlap <george.dunlap@citrix.com>
+Date: Fri, 22 Sep 2017 11:46:55 +0100
+Subject: [PATCH 2/2] x86/mm: Disable PV linear pagetables by default
+
+Allowing pagetables to point to other pagetables of the same level
+(often called 'linear pagetables') has been included in Xen since its
+inception. But it is not used by the most common PV guests (Linux,
+NetBSD, minios), and has been the source of a number of subtle
+reference-counting bugs.
+
+Add a command-line option to control whether PV linear pagetables are
+allowed (disabled by default).
+
+Reported-by: Jann Horn <jannh@google.com>
+Signed-off-by: George Dunlap <george.dunlap@citrix.com>
+Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
+---
+Changes since v2:
+- s/_/-/; in command-line option
+- Added __read_mostly
+---
+ docs/misc/xen-command-line.markdown | 15 +++++++++++++++
+ xen/arch/x86/mm.c | 10 ++++++++++
+ 2 files changed, 25 insertions(+)
+
+diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
+index 44d99852aa..45ef873abb 100644
+--- a/docs/misc/xen-command-line.markdown
++++ b/docs/misc/xen-command-line.markdown
+@@ -1374,6 +1374,21 @@ The following resources are available:
+ CDP, one COS will corespond two CBMs other than one with CAT, due to the
+ sum of CBMs is fixed, that means actual `cos_max` in use will automatically
+ reduce to half when CDP is enabled.
++
++### pv-linear-pt
++> `= <boolean>`
++
++> Default: `false`
++
++Allow PV guests to have pagetable entries pointing to other pagetables
++of the same level (i.e., allowing L2 PTEs to point to other L2 pages).
++This technique is often called "linear pagetables", and is sometimes
++used to allow operating systems a simple way to consistently map the
++current process's pagetables into its own virtual address space.
++
++None of the most common PV operating systems (Linux, NetBSD, MiniOS)
++use this technique, but there may be custom operating systems which
++do.
+
+ ### reboot
+ > `= t[riple] | k[bd] | a[cpi] | p[ci] | P[ower] | e[fi] | n[o] [, [w]arm | [c]old]`
+diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
+index 1e469bd354..32952a46b9 100644
+--- a/xen/arch/x86/mm.c
++++ b/xen/arch/x86/mm.c
+@@ -814,6 +814,9 @@ static void dec_linear_uses(struct page_info *pg)
+ * frame if it is mapped by a different root table. This is sufficient and
+ * also necessary to allow validation of a root table mapping itself.
+ */
++static bool __read_mostly pv_linear_pt_enable = false;
++boolean_param("pv-linear-pt", pv_linear_pt_enable);
++
+ #define define_get_linear_pagetable(level) \
+ static int \
+ get_##level##_linear_pagetable( \
+@@ -823,6 +826,13 @@ get_##level##_linear_pagetable( \
+ struct page_info *page; \
+ unsigned long pfn; \
+ \
++ if ( !pv_linear_pt_enable ) \
++ { \
++ gdprintk(XENLOG_WARNING, \
++ "Attempt to create linear p.t. (feature disabled)\n"); \
++ return 0; \
++ } \
++ \
+ if ( (level##e_get_flags(pde) & _PAGE_RW) ) \
+ { \
+ gdprintk(XENLOG_WARNING, \
+--
+2.14.1
+
diff --git a/system/xen/xsa/xsa241-4.9.patch b/system/xen/xsa/xsa241-4.9.patch
new file mode 100644
index 0000000000..514e4c7a4b
--- /dev/null
+++ b/system/xen/xsa/xsa241-4.9.patch
@@ -0,0 +1,120 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86: don't store possibly stale TLB flush time stamp
+
+While the timing window is extremely narrow, it is theoretically
+possible for an update to the TLB flush clock and a subsequent flush
+IPI to happen between the read and write parts of the update of the
+per-page stamp. Exclude this possibility by disabling interrupts
+across the update, preventing the IPI to be serviced in the middle.
+
+This is XSA-241.
+
+Reported-by: Jann Horn <jannh@google.com>
+Suggested-by: George Dunlap <george.dunlap@citrix.com>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: George Dunlap <george.dunlap@citrix.com>
+
+--- a/xen/arch/arm/smp.c
++++ b/xen/arch/arm/smp.c
+@@ -1,3 +1,4 @@
++#include <xen/mm.h>
+ #include <asm/system.h>
+ #include <asm/smp.h>
+ #include <asm/cpregs.h>
+--- a/xen/arch/x86/mm.c
++++ b/xen/arch/x86/mm.c
+@@ -2524,7 +2524,7 @@ static int _put_final_page_type(struct p
+ */
+ if ( !(shadow_mode_enabled(page_get_owner(page)) &&
+ (page->count_info & PGC_page_table)) )
+- page->tlbflush_timestamp = tlbflush_current_time();
++ page_set_tlbflush_timestamp(page);
+ wmb();
+ page->u.inuse.type_info--;
+ }
+@@ -2534,7 +2534,7 @@ static int _put_final_page_type(struct p
+ (PGT_count_mask|PGT_validated|PGT_partial)) == 1);
+ if ( !(shadow_mode_enabled(page_get_owner(page)) &&
+ (page->count_info & PGC_page_table)) )
+- page->tlbflush_timestamp = tlbflush_current_time();
++ page_set_tlbflush_timestamp(page);
+ wmb();
+ page->u.inuse.type_info |= PGT_validated;
+ }
+@@ -2588,7 +2588,7 @@ static int _put_page_type(struct page_in
+ if ( ptpg && PGT_type_equal(x, ptpg->u.inuse.type_info) )
+ {
+ /*
+- * page_set_tlbflush_timestamp() accesses the same union
++ * set_tlbflush_timestamp() accesses the same union
+ * linear_pt_count lives in. Unvalidated page table pages,
+ * however, should occur during domain destruction only
+ * anyway. Updating of linear_pt_count luckily is not
+@@ -2609,7 +2609,7 @@ static int _put_page_type(struct page_in
+ */
+ if ( !(shadow_mode_enabled(page_get_owner(page)) &&
+ (page->count_info & PGC_page_table)) )
+- page->tlbflush_timestamp = tlbflush_current_time();
++ page_set_tlbflush_timestamp(page);
+ }
+
+ if ( likely((y = cmpxchg(&page->u.inuse.type_info, x, nx)) == x) )
+--- a/xen/arch/x86/mm/shadow/common.c
++++ b/xen/arch/x86/mm/shadow/common.c
+@@ -1464,7 +1464,7 @@ void shadow_free(struct domain *d, mfn_t
+ * TLBs when we reuse the page. Because the destructors leave the
+ * contents of the pages in place, we can delay TLB flushes until
+ * just before the allocator hands the page out again. */
+- sp->tlbflush_timestamp = tlbflush_current_time();
++ page_set_tlbflush_timestamp(sp);
+ perfc_decr(shadow_alloc_count);
+ page_list_add_tail(sp, &d->arch.paging.shadow.freelist);
+ sp = next;
+--- a/xen/common/page_alloc.c
++++ b/xen/common/page_alloc.c
+@@ -960,7 +960,7 @@ static void free_heap_pages(
+ /* If a page has no owner it will need no safety TLB flush. */
+ pg[i].u.free.need_tlbflush = (page_get_owner(&pg[i]) != NULL);
+ if ( pg[i].u.free.need_tlbflush )
+- pg[i].tlbflush_timestamp = tlbflush_current_time();
++ page_set_tlbflush_timestamp(&pg[i]);
+
+ /* This page is not a guest frame any more. */
+ page_set_owner(&pg[i], NULL); /* set_gpfn_from_mfn snoops pg owner */
+--- a/xen/include/asm-arm/flushtlb.h
++++ b/xen/include/asm-arm/flushtlb.h
+@@ -12,6 +12,11 @@ static inline void tlbflush_filter(cpuma
+
+ #define tlbflush_current_time() (0)
+
++static inline void page_set_tlbflush_timestamp(struct page_info *page)
++{
++ page->tlbflush_timestamp = tlbflush_current_time();
++}
++
+ #if defined(CONFIG_ARM_32)
+ # include <asm/arm32/flushtlb.h>
+ #elif defined(CONFIG_ARM_64)
+--- a/xen/include/asm-x86/flushtlb.h
++++ b/xen/include/asm-x86/flushtlb.h
+@@ -23,6 +23,20 @@ DECLARE_PER_CPU(u32, tlbflush_time);
+
+ #define tlbflush_current_time() tlbflush_clock
+
++static inline void page_set_tlbflush_timestamp(struct page_info *page)
++{
++ /*
++ * Prevent storing a stale time stamp, which could happen if an update
++ * to tlbflush_clock plus a subsequent flush IPI happen between the
++ * reading of tlbflush_clock and the writing of the struct page_info
++ * field.
++ */
++ ASSERT(local_irq_is_enabled());
++ local_irq_disable();
++ page->tlbflush_timestamp = tlbflush_current_time();
++ local_irq_enable();
++}
++
+ /*
+ * @cpu_stamp is the timestamp at last TLB flush for the CPU we are testing.
+ * @lastuse_stamp is a timestamp taken when the PFN we are testing was last
diff --git a/system/xen/xsa/xsa242-4.9.patch b/system/xen/xsa/xsa242-4.9.patch
new file mode 100644
index 0000000000..8adfa61fd7
--- /dev/null
+++ b/system/xen/xsa/xsa242-4.9.patch
@@ -0,0 +1,43 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: x86: don't allow page_unlock() to drop the last type reference
+
+Only _put_page_type() does the necessary cleanup, and hence not all
+domain pages can be released during guest cleanup (leaving around
+zombie domains) if we get this wrong.
+
+This is XSA-242.
+
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+
+--- a/xen/arch/x86/mm.c
++++ b/xen/arch/x86/mm.c
+@@ -1923,7 +1923,11 @@ void page_unlock(struct page_info *page)
+
+ do {
+ x = y;
++ ASSERT((x & PGT_count_mask) && (x & PGT_locked));
++
+ nx = x - (1 | PGT_locked);
++ /* We must not drop the last reference here. */
++ ASSERT(nx & PGT_count_mask);
+ } while ( (y = cmpxchg(&page->u.inuse.type_info, x, nx)) != x );
+ }
+
+@@ -2611,6 +2615,17 @@ static int _put_page_type(struct page_in
+ (page->count_info & PGC_page_table)) )
+ page_set_tlbflush_timestamp(page);
+ }
++ else if ( unlikely((nx & (PGT_locked | PGT_count_mask)) ==
++ (PGT_locked | 1)) )
++ {
++ /*
++ * We must not drop the second to last reference when the page is
++ * locked, as page_unlock() doesn't do any cleanup of the type.
++ */
++ cpu_relax();
++ y = page->u.inuse.type_info;
++ continue;
++ }
+
+ if ( likely((y = cmpxchg(&page->u.inuse.type_info, x, nx)) == x) )
+ break;
diff --git a/system/xen/xsa/xsa243.patch b/system/xen/xsa/xsa243.patch
new file mode 100644
index 0000000000..aaff277514
--- /dev/null
+++ b/system/xen/xsa/xsa243.patch
@@ -0,0 +1,93 @@
+From: Andrew Cooper <andrew.cooper3@citrix.com>
+Subject: x86/shadow: Don't create self-linear shadow mappings for 4-level translated guests
+
+When initially creating a monitor table for 4-level translated guests, don't
+install a shadow-linear mapping. This mapping is actually self-linear, and
+trips up the writeable heuristic logic into following Xen's mappings, not the
+guests' shadows it was expecting to follow.
+
+A consequence of this is that sh_guess_wrmap() needs to cope with there being
+no shadow-linear mapping present, which in practice occurs once each time a
+vcpu switches to 4-level paging from a different paging mode.
+
+An appropriate shadow-linear slot will be inserted into the monitor table
+either while constructing lower level monitor tables, or by sh_update_cr3().
+
+While fixing this, clarify the safety of the other mappings. Despite
+appearing unsafe, it is correct to create a guest-linear mapping for
+translated domains; this is self-linear and doesn't point into the translated
+domain. Drop a dead clause for translate != external guests.
+
+This is XSA-243.
+
+Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
+Acked-by: Tim Deegan <tim@xen.org>
+
+diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
+index 8d4f244..a18d286 100644
+--- a/xen/arch/x86/mm/shadow/multi.c
++++ b/xen/arch/x86/mm/shadow/multi.c
+@@ -1485,26 +1485,38 @@ void sh_install_xen_entries_in_l4(struct domain *d, mfn_t gl4mfn, mfn_t sl4mfn)
+ sl4e[shadow_l4_table_offset(RO_MPT_VIRT_START)] = shadow_l4e_empty();
+ }
+
+- /* Shadow linear mapping for 4-level shadows. N.B. for 3-level
+- * shadows on 64-bit xen, this linear mapping is later replaced by the
+- * monitor pagetable structure, which is built in make_monitor_table
+- * and maintained by sh_update_linear_entries. */
+- sl4e[shadow_l4_table_offset(SH_LINEAR_PT_VIRT_START)] =
+- shadow_l4e_from_mfn(sl4mfn, __PAGE_HYPERVISOR_RW);
+-
+- /* Self linear mapping. */
+- if ( shadow_mode_translate(d) && !shadow_mode_external(d) )
++ /*
++ * Linear mapping slots:
++ *
++ * Calling this function with gl4mfn == sl4mfn is used to construct a
++ * monitor table for translated domains. In this case, gl4mfn forms the
++ * self-linear mapping (i.e. not pointing into the translated domain), and
++ * the shadow-linear slot is skipped. The shadow-linear slot is either
++ * filled when constructing lower level monitor tables, or via
++ * sh_update_cr3() for 4-level guests.
++ *
++ * Calling this function with gl4mfn != sl4mfn is used for non-translated
++ * guests, where the shadow-linear slot is actually self-linear, and the
++ * guest-linear slot points into the guests view of its pagetables.
++ */
++ if ( shadow_mode_translate(d) )
+ {
+- // linear tables may not be used with translated PV guests
+- sl4e[shadow_l4_table_offset(LINEAR_PT_VIRT_START)] =
++ ASSERT(mfn_eq(gl4mfn, sl4mfn));
++
++ sl4e[shadow_l4_table_offset(SH_LINEAR_PT_VIRT_START)] =
+ shadow_l4e_empty();
+ }
+ else
+ {
+- sl4e[shadow_l4_table_offset(LINEAR_PT_VIRT_START)] =
+- shadow_l4e_from_mfn(gl4mfn, __PAGE_HYPERVISOR_RW);
++ ASSERT(!mfn_eq(gl4mfn, sl4mfn));
++
++ sl4e[shadow_l4_table_offset(SH_LINEAR_PT_VIRT_START)] =
++ shadow_l4e_from_mfn(sl4mfn, __PAGE_HYPERVISOR_RW);
+ }
+
++ sl4e[shadow_l4_table_offset(LINEAR_PT_VIRT_START)] =
++ shadow_l4e_from_mfn(gl4mfn, __PAGE_HYPERVISOR_RW);
++
+ unmap_domain_page(sl4e);
+ }
+ #endif
+@@ -4405,6 +4417,11 @@ static int sh_guess_wrmap(struct vcpu *v, unsigned long vaddr, mfn_t gmfn)
+
+ /* Carefully look in the shadow linear map for the l1e we expect */
+ #if SHADOW_PAGING_LEVELS >= 4
++ /* Is a shadow linear map is installed in the first place? */
++ sl4p = v->arch.paging.shadow.guest_vtable;
++ sl4p += shadow_l4_table_offset(SH_LINEAR_PT_VIRT_START);
++ if ( !(shadow_l4e_get_flags(*sl4p) & _PAGE_PRESENT) )
++ return 0;
+ sl4p = sh_linear_l4_table(v) + shadow_l4_linear_offset(vaddr);
+ if ( !(shadow_l4e_get_flags(*sl4p) & _PAGE_PRESENT) )
+ return 0;
diff --git a/system/xen/xsa/xsa244.patch b/system/xen/xsa/xsa244.patch
new file mode 100644
index 0000000000..c35a80be32
--- /dev/null
+++ b/system/xen/xsa/xsa244.patch
@@ -0,0 +1,59 @@
+From: Andrew Cooper <andrew.cooper3@citrix.com>
+Subject: [PATCH] x86/cpu: Fix IST handling during PCPU bringup
+
+Clear IST references in newly allocated IDTs. Nothing good will come of
+having them set before the TSS is suitably constructed (although the chances
+of the CPU surviving such an IST interrupt/exception is extremely slim).
+
+Uniformly set the IST references after the TSS is in place. This fixes an
+issue on AMD hardware, where onlining a PCPU while PCPU0 is in HVM context
+will cause IST_NONE to be copied into the new IDT, making that PCPU vulnerable
+to privilege escalation from PV guests until it subsequently schedules an HVM
+guest.
+
+This is XSA-244
+
+Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
+Reviewed-by: Jan Beulich <jbeulich@suse.com>
+---
+ xen/arch/x86/cpu/common.c | 5 +++++
+ xen/arch/x86/smpboot.c | 3 +++
+ 2 files changed, 8 insertions(+)
+
+diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
+index 78f5667..6cf3628 100644
+--- a/xen/arch/x86/cpu/common.c
++++ b/xen/arch/x86/cpu/common.c
+@@ -640,6 +640,7 @@ void __init early_cpu_init(void)
+ * - Sets up TSS with stack pointers, including ISTs
+ * - Inserts TSS selector into regular and compat GDTs
+ * - Loads GDT, IDT, TR then null LDT
++ * - Sets up IST references in the IDT
+ */
+ void load_system_tables(void)
+ {
+@@ -702,6 +703,10 @@ void load_system_tables(void)
+ asm volatile ("ltr %w0" : : "rm" (TSS_ENTRY << 3) );
+ asm volatile ("lldt %w0" : : "rm" (0) );
+
++ set_ist(&idt_tables[cpu][TRAP_double_fault], IST_DF);
++ set_ist(&idt_tables[cpu][TRAP_nmi], IST_NMI);
++ set_ist(&idt_tables[cpu][TRAP_machine_check], IST_MCE);
++
+ /*
+ * Bottom-of-stack must be 16-byte aligned!
+ *
+diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
+index 3ca716c..1609b62 100644
+--- a/xen/arch/x86/smpboot.c
++++ b/xen/arch/x86/smpboot.c
+@@ -724,6 +724,9 @@ static int cpu_smpboot_alloc(unsigned int cpu)
+ if ( idt_tables[cpu] == NULL )
+ goto oom;
+ memcpy(idt_tables[cpu], idt_table, IDT_ENTRIES * sizeof(idt_entry_t));
++ set_ist(&idt_tables[cpu][TRAP_double_fault], IST_NONE);
++ set_ist(&idt_tables[cpu][TRAP_nmi], IST_NONE);
++ set_ist(&idt_tables[cpu][TRAP_machine_check], IST_NONE);
+
+ for ( stub_page = 0, i = cpu & ~(STUBS_PER_PAGE - 1);
+ i < nr_cpu_ids && i <= (cpu | (STUBS_PER_PAGE - 1)); ++i )
diff --git a/system/xen/xsa/xsa245-0001-xen-page_alloc-Cover-memory-unreserved-after-boot-in.patch b/system/xen/xsa/xsa245-0001-xen-page_alloc-Cover-memory-unreserved-after-boot-in.patch
new file mode 100644
index 0000000000..2047686903
--- /dev/null
+++ b/system/xen/xsa/xsa245-0001-xen-page_alloc-Cover-memory-unreserved-after-boot-in.patch
@@ -0,0 +1,48 @@
+From a48d47febc1340f27d6c716545692641a09b414c Mon Sep 17 00:00:00 2001
+From: Julien Grall <julien.grall@arm.com>
+Date: Thu, 21 Sep 2017 14:13:08 +0100
+Subject: [PATCH 1/2] xen/page_alloc: Cover memory unreserved after boot in
+ first_valid_mfn
+
+On Arm, some regions (e.g Initramfs, Dom0 Kernel...) are marked as
+reserved until the hardware domain is built and they are copied into its
+memory. Therefore, they will not be added in the boot allocator via
+init_boot_pages.
+
+Instead, init_xenheap_pages will be called once the region are not used
+anymore.
+
+Update first_valid_mfn in both init_heap_pages and init_boot_pages
+(already exist) to cover all the cases.
+
+Signed-off-by: Julien Grall <julien.grall@arm.com>
+[Adjust comment, added locking around first_valid_mfn update]
+Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
+---
+ xen/common/page_alloc.c | 10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
+index 0b9f6cc6df..fbe5a8af39 100644
+--- a/xen/common/page_alloc.c
++++ b/xen/common/page_alloc.c
+@@ -1700,6 +1700,16 @@ static void init_heap_pages(
+ {
+ unsigned long i;
+
++ /*
++ * Some pages may not go through the boot allocator (e.g reserved
++ * memory at boot but released just after --- kernel, initramfs,
++ * etc.).
++ * Update first_valid_mfn to ensure those regions are covered.
++ */
++ spin_lock(&heap_lock);
++ first_valid_mfn = min_t(unsigned long, page_to_mfn(pg), first_valid_mfn);
++ spin_unlock(&heap_lock);
++
+ for ( i = 0; i < nr_pages; i++ )
+ {
+ unsigned int nid = phys_to_nid(page_to_maddr(pg+i));
+--
+2.11.0
+
diff --git a/system/xen/xsa/xsa245-0002-xen-arm-Correctly-report-the-memory-region-in-the-du.patch b/system/xen/xsa/xsa245-0002-xen-arm-Correctly-report-the-memory-region-in-the-du.patch
new file mode 100644
index 0000000000..cd4d2709be
--- /dev/null
+++ b/system/xen/xsa/xsa245-0002-xen-arm-Correctly-report-the-memory-region-in-the-du.patch
@@ -0,0 +1,73 @@
+From cbfcf039d0e0b6f4c4cb3de612f7bf788a0c47cd Mon Sep 17 00:00:00 2001
+From: Julien Grall <julien.grall@arm.com>
+Date: Mon, 18 Sep 2017 14:24:08 +0100
+Subject: [PATCH 2/2] xen/arm: Correctly report the memory region in the dummy
+ NUMA helpers
+
+NUMA is currently not supported on Arm. Because common code is
+NUMA-aware, dummy helpers are instead provided to expose a single node.
+
+Those helpers are for instance used to know the region to scrub.
+
+However the memory region is not reported correctly. Indeed, the
+frametable may not be at the beginning of the memory and there might be
+multiple memory banks. This will lead to not scrub some part of the
+memory.
+
+The memory information can be found using:
+ * first_valid_mfn as the start of the memory
+ * max_page - first_valid_mfn as the spanned pages
+
+Note that first_valid_mfn is now been exported. The prototype has been
+added in asm-arm/numa.h and not in a common header because I would
+expect the variable to become static once NUMA is fully supported on
+Arm.
+
+Signed-off-by: Julien Grall <julien.grall@arm.com>
+---
+ xen/common/page_alloc.c | 6 +++++-
+ xen/include/asm-arm/numa.h | 10 ++++++++--
+ 2 files changed, 13 insertions(+), 3 deletions(-)
+
+diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
+index fbe5a8af39..472c6fe329 100644
+--- a/xen/common/page_alloc.c
++++ b/xen/common/page_alloc.c
+@@ -192,7 +192,11 @@ PAGE_LIST_HEAD(page_broken_list);
+ * BOOT-TIME ALLOCATOR
+ */
+
+-static unsigned long __initdata first_valid_mfn = ~0UL;
++/*
++ * first_valid_mfn is exported because it is use in ARM specific NUMA
++ * helpers. See comment in asm-arm/numa.h.
++ */
++unsigned long first_valid_mfn = ~0UL;
+
+ static struct bootmem_region {
+ unsigned long s, e; /* MFNs @s through @e-1 inclusive are free */
+diff --git a/xen/include/asm-arm/numa.h b/xen/include/asm-arm/numa.h
+index a2c1a3476d..3e7384da9e 100644
+--- a/xen/include/asm-arm/numa.h
++++ b/xen/include/asm-arm/numa.h
+@@ -12,9 +12,15 @@ static inline __attribute__((pure)) nodeid_t phys_to_nid(paddr_t addr)
+ return 0;
+ }
+
++/*
++ * TODO: make first_valid_mfn static when NUMA is supported on Arm, this
++ * is required because the dummy helpers is using it.
++ */
++extern unsigned long first_valid_mfn;
++
+ /* XXX: implement NUMA support */
+-#define node_spanned_pages(nid) (total_pages)
+-#define node_start_pfn(nid) (pdx_to_pfn(frametable_base_pdx))
++#define node_spanned_pages(nid) (max_page - first_valid_mfn)
++#define node_start_pfn(nid) (first_valid_mfn)
+ #define __node_distance(a, b) (20)
+
+ static inline unsigned int arch_get_dma_bitsize(void)
+--
+2.11.0
+